Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description adds context beyond the `destructiveHint` annotation by noting that the tool consumes API quota and is asynchronous by default. It explains the return behavior (pending vs finished screenshot) and mentions the API endpoint, providing good transparency.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is three sentences, front-loaded with the main purpose, and each sentence provides critical information without redundancy. It is concise and well-structured.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the lack of an output schema, the description covers the return types (pending vs finished screenshot) and the API endpoint. It does not detail the screenshot object structure, but that is likely acceptable for a capture tool. The information is sufficient for most use cases.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% with parameter descriptions already present. The description adds minimal extra meaning beyond the schema, such as the context for `synchronous` (async by default) and the word 'Public' for URL, but does not significantly enhance understanding of each parameter.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states 'Capture a screenshot of a web page', which is a specific verb+resource combination. The tool name and title reinforce this, and it is distinct from sibling tools which deal with collections, images, videos, etc.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explains the default async behavior and when to set synchronous=true for blocking. It does not explicitly state when not to use the tool or compare to alternatives, but the guidance on async vs sync is clear and useful.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.